echarts中几种渐变方式的具体实现方式

JavaScript/前端
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2023-06-16
目录
  • 在echarts 中实现渐变的具体几种方式
  • 方式一:
  • 方式二:colorStops
  • 总结

在echarts 中实现渐变的具体几种方式

在我们日常使用Echarts图表过程中,会遇到一些要求我们的echarts图表能实现颜色渐变,以下几种方式就能满足你的需求。文档参考 ECharts option 文档

方式一:

线性渐变:new echarts.graphic.LinearGradient(x,y,x2,y2,offset,boolean)

  • x,y,x2,y2,包围框中的百分比,数值范围 0-1;
  • offset,类似颜色线性梯度,数值范围 0-1;
  • boolean,默认false,若最后参数为true,前四个参数将使用像素位置。

径向渐变:new echarts.graphic.RadialGradient(x,y,r,offset,boolean)

  • x,y,代表圆心,数值范围 0-1;
  • r,代表半径,数值范围 0-1;
  • offset,类似颜色线性梯度,数值范围 0-1;
  • boolean,默认false,若最后参数为true,前四个参数将使用像素位置。

采用图片显示:new echarts.graphic.Pattern(imageDom,repeat)

  • imageDom,仅支持 HTMLImageElement 和 HTMLCanvasElement形式图片;
  • repeat,默认’repeat’,可取值还有’repeat-x’, ‘repeat-y’, or ‘no-repeat’;

代码示例:

// 创建 HTMLImageElement
// HTMLCanvasElement请自行研究去
var imageDom = new Image(); // Image 构造函数
imageDom.src = '/static/img/map_bg.png'; // 图片路径
imageDom.alt = '这是一张图片';

// 应用如下
// color:{
//   image: imageDom, // 支持为 HTMLImageElement, HTMLCanvasElement,不支持路径字符串
//    repeat: 'repeat' // 是否平铺,可以是 'repeat-x', 'repeat-y', 'no-repeat'
// }

方式二:colorStops

线性渐变:colorStops - linear

  • type:‘linear’,线性渐变
  • x,y,x2,y2,代表包围框中的百分比,数值范围 0-1;
  • colorStops,类似颜色线性梯度,数值范围 0-1;
  • global,默认false

径向渐变:colorStops - radial

  • type:‘radial’,径向渐变
  • x,y,代表圆心,数值范围 0-1;
  • r,代表半径,数值范围 0-1;
  • colorStops,类似颜色线性梯度,数值范围 0-1;
  • global,默认false

效果图:

代码如下:

var imageDom = new Image(); // Image 构造函数
imageDom.src = 'https://github.com/iuvc/magicJs/blob/main/public/images/issues/blue-white-background.jpg?raw=true';
imageDom.alt = '测试';
option = {
  title: {
    text: 'echarts 渐变',
    left: 'center'
  },
  tooltip: {
    trigger: 'item',
    formatter: '{a} <br/>{b} : {c} ({d}%)'
  },
  legend: {
    top:,
    left:,
    orient: 'vertical',
    data: [
      '线性渐变区域 LinearGradient',
      '径向渐变区域 RadialGradient',
      '线性渐变区域 ColorStep-linear',
      '径向渐变区域 ColorStep-radial',
      '图片显示'
    ]
  },
  series: [
    {
      name: 'Radius Mode',
      type: 'pie',
      radius: [, '70%'],
      center: ['%', '50%'],
      roseType: 'radius',
      itemStyle: {
        borderRadius:
      },
      label: {
        show: true
      },
      emphasis: {
        label: {
          show: true
        }
      },
      data: [
        {
          value:,
          name: '线性渐变区域 LinearGradient',
          itemStyle: {
            //  线性渐变方式一 ======================================================
            // LinearGradient前四个分参数别代表右,下,左,上,数值-1
            color: new echarts.graphic.LinearGradient(, 0, 0, 1, [
              {
                offset:,
                color: 'rgba(,174,19,0.7)'
              },
              {
                offset:,
                color: 'rgba(,174,19,0.05)'
              }
            ])
          }
        },
        {
          value:,
          name: '径向渐变区域 RadialGradient',
          itemStyle: {
            //  径向渐变方式一 ======================================================
            // RadialGradient前三个分参数别代表圆心(x,y),半径(数值-1)
            color: new echarts.graphic.RadialGradient(.5, 0.5, 0.8, [
              {
                offset:,
                color: 'rgba(,154,119,1)'
              },
              {
                offset:,
                color: 'rgba(,154,119,0.05)'
              }
            ])
          }
        },
        {
          value:,
          name: '线性渐变区域 ColorStep-linear',
          itemStyle: {
            //  线性渐变方式二 ======================================================
            // x,y,x,y2数值同LinearGradient前四个参数分别代表右,下,左,上,数值0-1
            color: {
              type: 'linear',
              x:,
              y:,
              x: 0,
              y: 1,
              colorStops: [
                {
                  offset:,
                  color: 'rgba(,216,208,0.7)' // 0% 处的颜色
                },
                {
                  offset:,
                  color: 'rgba(,216,208,0.05)' // 100% 处的颜色
                }
              ],
              global: false // 缺省为 false
            }
          }
        },
        {
          value:,
          name: '径向渐变区域 ColorStep-radial',
          itemStyle: {
            //  径向渐变方式二 ======================================================
            // x.5 y 0.5 代表圆心,r 代表半径
            color: {
              type: 'radial',
              x:.5,
              y:.5,
              r:.9,
              colorStops: [
                {
                  offset:,
                  color: 'rgba(,216,60, 0.7)' // 0% 处的颜色
                },
                {
                  offset:,
                  color: 'rgba(,216,60, 0.05)' // 100% 处的颜色
                }
              ],
              global: false // 缺省为 false
            }
          }
        },
        { 
            value:, 
            name: '图片显示' ,
            itemStyle: {
            //  图片显示 ======================================================
                color: {
                  image: imageDom, // 支持为 HTMLImageElement, HTMLCanvasElement,不支持路径字符串
                  repeat: 'repeat' // 是否平铺,可以是 'repeat-x', 'repeat-y', 'no-repeat'
                }
            }
        }
      ]
    }
  ]
};

其他示例:

代码如下:

option = {
  title: {
    text: '渐变区域图'
  },
  tooltip: {
    trigger: 'axis',
    axisPointer: {
      type: 'cross',
      label: {
        backgroundColor: '#a7985'
      }
    }
  },
  legend: {
    top:,
    data: [
      '线性渐变区域 LinearGradient',
      '线性渐变区域 ColorStep-linear',
      '径向渐变区域 ColorStep-radial',
      '径向渐变区域 RadialGradient'
    ]
  },
  grid: {
    top:,
    left:,
    right:,
    bottom:
  },
  xAxis: [
    {
      type: 'category',
      boundaryGap: true,
      axisLine: {
        show: false,
        onZero: true,
        lineStyle: {
          color: '#'
        }
      },
      splitLine: {
        show: false
      },
      axisTick: {
        show: false
      },
      data: [
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15',
        ':30',
        ':45',
        ':00',
        ':15'
      ]
    }
  ],
  yAxis: [
    {
      type: 'category',
      boundaryGap: true,
      axisLine: {
        show: false,
        onZero: true,
        lineStyle: {
          color: '#'
        }
      },
      splitLine: {
        show: false
      },
      axisTick: {
        show: false
      }
    }
  ],
  series: [
    {
      name: '线性渐变区域 LinearGradient',
      type: 'line',
      stack: '总量',
      data: [.67, 1.25, 1.02, 1.44, 1.81, 1.13, 1.58, 1.13, 1.56, 1.3, 1.9, 1.3,
.55, 1.94, 1.69, 1.69, 1.8, 1.21, 1.29, 1.58, 1.04, 1.67, 1.07, 1.18,
.57, 1.05, 1.63, 1.28, 1.28, 1.58, 1.88, 1.2, 1.63, 1.59, 1.43, 1.25,
.68, 1.25, 1.12, 1.31, 1.6, 1.62, 1.57, 1.2, 1.02, 1.42, 1.91, 1.97,
.32, 1.06, 1.3, 1.22, 1.74, 1.02, 1.75, 1.2
      ],
      areaStyle: {
        color: new echarts.graphic.LinearGradient(, 0, 0, 1, [
          {
            offset:,
            color: 'rgba(,174,19,0.7)'
          },
          {
            offset:,
            color: 'rgba(,174,19,0.05)'
          }
        ])
      },
      itemStyle: {
        color: 'rgba(,174,19,.1)'
      },
      lineStyle: {
        color: 'rgba(,174,19,.1)'
      },
      smooth: true,
      smoothMonotone: 'x',
      symbol: 'circle'
    },
    {
      name: '线性渐变区域 ColorStep-linear',
      type: 'line',
      stack: '总量',
      data: [.31, 2.27, 1.64, 1.56, 1.75, 1.62, 2.18, 2.12, 1.97, 2.45, 2.39, 2.3,
.78, 1.82, 1.82, 1.76, 1.78, 1.63, 1.54, 1.6, 1.61, 1.68, 1.67, 1.67,
.34, 1.69, 2.18, 2.25, 2.44, 2.4, 1.97, 2.05, 2.05, 2.46, 1.62, 1.66,
.66, 1.87, 1.59, 1.99, 2.45, 2.05, 1.53, 2.39, 1.77, 1.99, 2.14, 2.33,
.55, 1.87, 1.65, 2.02, 1.68, 2.13, 1.88, 2.19
      ],
      areaStyle: {
        color: {
          type: 'linear',
          x:,
          y:,
          x: 0,
          y: 1,
          colorStops: [
            {
              offset:,
              color: 'rgba(,216,208,0.7)' // 0% 处的颜色
            },
            {
              offset:,
              color: 'rgba(,216,208,0.05)' // 100% 处的颜色
            }
          ],
          global: false // 缺省为 false
        }
      },
      itemStyle: {
        color: 'rgba(,216,208,.1)'
      },
      lineStyle: {
        color: 'rgba(,216,208,.1)'
      },
      smooth: true,
      smoothMonotone: 'x',
      symbol: 'circle'
    },
    {
      name: '径向渐变区域 RadialGradient',
      type: 'line',
      stack: '总量',
      label: {
        normal: {
          show: true,
          position: 'top'
        }
      },
      data: [.69, 2.47, 2.53, 3.31, 3.25, 3.12, 2.66, 2.58, 3.01, 3.21, 2.69, 2.72,
.67, 3.34, 3.21, 2.79, 3.23, 3.07, 2.84, 2.46, 3.25, 2.92, 2.42, 2.61,
.83, 3.29, 2.44, 3.38, 2.82, 2.56, 2.94, 2.42, 2.95, 2.82, 3.18, 2.6,
.91, 3.07, 2.57, 2.45, 2.45, 2.94, 2.86, 3.12, 3.07, 3.02, 2.53, 2.64,
.97, 2.62, 2.79, 2.68, 3.24, 3.38, 2.67, 3.17
      ],
      areaStyle: {
        color: new echarts.graphic.RadialGradient(.5, 0.5, 0.8, [
          {
            offset:,
            color: 'rgba(,154,119,.7)'
          },
          {
            offset:,
            color: 'rgba(,154,119,0.05)'
          }
        ])
      },
      itemStyle: {
        color: 'rgba(,154,119,.1)'
      },
      lineStyle: {
        color: 'rgba(,154,119,.1)'
      },
      smooth: true,
      smoothMonotone: 'x',
      symbol: 'circle'
    },
    {
      name: '径向渐变区域 ColorStep-radial',
      type: 'line',
      stack: '总量',
      label: {
        normal: {
          show: true,
          position: 'top'
        }
      },
      data: [.79, 2.57, 2.63, 3.41, 3.35, 3.22, 2.76, 2.68, 3.11, 3.31, 2.79, 2.82,
.77, 3.44, 3.31, 2.89, 3.33, 3.17, 2.94, 2.56, 3.35, 3.02, 2.52, 2.71,
.93, 3.39, 2.54, 3.48, 2.92, 2.66, 3.04, 2.52, 3.05, 2.92, 3.28, 2.7,
.01, 3.17, 2.67, 2.55, 2.55, 3.04, 2.96, 3.22, 3.17, 3.12, 2.63, 2.74,
.07, 2.72, 2.89, 2.78, 3.34, 3.48, 2.77, 3.27
      ],
      areaStyle: {
        color: {
          type: 'radial',
          x:.5,
          y:.5,
          r:.9,
          colorStops: [
            {
              offset:,
              color: 'rgba(,216,60, 0.7)' // 0% 处的颜色
            },
            {
              offset:,
              color: 'rgba(,216,60, 0.05)' // 100% 处的颜色
            }
          ],
          global: false // 缺省为 false
        }
      },
      itemStyle: {
        color: 'rgba(,216,60,.1)'
      },
      lineStyle: {
        color: 'rgba(,216,60,.1)'
      },
      smooth: true,
      smoothMonotone: 'x',
      symbol: 'circle'
    }
  ]
};